PwC Hails “Groundbreaking Potential” of Drone Audit

Professional services giant PwC has conducted its first stock audit using a drone, in a move it believes can rapidly cut audit times, reduce risk and prevent downtime.

A drone developed by UK-based QuestUAV was used in the audit of coal supplies for one of the UK’s last remaining coal-fired power stations. It was conducted on behalf of German utility RWE by PwC, which employs over 250,000 people.

Its successful execution looks set to open the doors to much wider deployment of unmanned aerial vehicles (UAVs) in such stock audits, with PwC saying: “Based on our results, the potential is groundbreaking”.

PwC Drone Audit: 99% Accurate

Using a drone, PwC collected over 300 images of the coal reserve which were then stitched together using the photogrammetry process (the science of making measurements from photographs) to determine matching data points.

The drone captured c.900 data points per cubic meters giving the data an accuracy of 2cm, PwC said, adding that the value of the coal was then calculated to within 99+% accuracy based on that volume measurement.

The drone used by PwC. Credit: PwC

The traditional method to measure coal piles involves manually moving across the coal with two metre GPS tracking poles. This process take four hours while the drone can do the task in half an hour.

The manual method also poses a significant risk for workers as parts of the coal pile can slide during the measurement. Machines working on the coal reserve also need to be shut down during a manual audit, but as the drone is not on the actual coal pile it allows work to continue without disruption.

“Powerful New Perspective”

Elaine Whyte UK drones leader at PwC said in a release: “This trial with RWE is the first time PwC has used drones for audit stock count purposes. It demonstrates the powerful new perspective that we believe drones can offer for businesses across a wide variety of industries.”

“Sectors with large assets in hard to reach areas are the most obvious starting points for expanding this kind of work further – from mining to agriculture and forestry.”

The drone used in the audit was a QuestUAV DATAhawk ppk mapping drone.

The fixed wing drone has a max speed of 100 Kph and can maintain flight for 45 minutes. The drone has a take-off weight of 2150g and can be hand-launched, or deployed from an air dock launch system.

PwC used the data gathered by the drone to create a digital twin of the coal reserve which the audit team could then view and interact with via PwC’s geospatial application which visualises the mine inventory.

Digital Twin of Coal ReserveImage Source: PwC

The data gathered from the drone survey mapping of the coal reserve will allow RWE to efficiently plan and monitor its site in Aberthaw which spans over 200 hectares.

Richard French, audit partner at PwC, commented: “While the traditional method remains reliable and will still be used for RWE’s formal year-end financial statements, the drone trial was conducted to explore ways of challenging the traditional method of stock counting. It was a classic example of new technology challenging the old – and based on our results, the potential is groundbreaking.”